1. Field of the Invention
The present invention relates to an image processing apparatus, an image processing method, and a program.
2. Description of the Related Art
To monitor or track an object such as a person or vehicle contained in an image photographed by an image photographing means such as a surveillance camera (ITV camera), it is first necessary for an object in an image to be detected. For example, a system of a monitoring apparatus using a surveillance camera is constructed in which a place to be monitored such as an off-limits area is photographed by the camera, presence/absence of any object contained in the image is detected, and raises an alarm when an object (suspicious object) enters the monitoring place being photographed.
When an object in the image makes an entry, brightness of the object area, that is, a luminance value of the object area in the image changes. Thus, an object can be detected by detecting an area where a difference in luminance value in the image arises as a differential area. However, if the monitoring place is the sea, a desert, grassland or the like, such a technique based on a change in luminance value over time poses an issue that other objects than detection objects may erroneously be detected because water, sand, and grass other than ships, persons, and vehicles to be detected also move.
Japanese Patent Application Laid-Open No. 2008-46769 is a technology that stably monitors for entries of suspicious-looking persons or objects from image data obtained from a surveillance camera intended for monitoring a place like the sea, a desert, or grassland where fluctuations are caused in a photographing screen mainly by natural phenomena.